Core form for casting concrete



Aug. 5, 1947. A. E. TROIEL I 2 ,1

CORE FORM FOR CASTING CONCRETE TUBES Filed Jan. 13, 1945 2 Sheets-Sheetl INVENTOR.

ARTHUR E. TPO/EL ATTORNE KS Aug. 5, 1947. A. E. TROIEL 7 CORE FORM FORCASTING CONCRETE TUBES Filed Jan. 13, 1945 2 Sheets-S heet 2 IN VEN TOR.

ARTHUR E. T/PO/EL ATTORNEYS patented Aug. 5, 1947 UNITED STATES PATENTOFFICE CORE FORM FOR CASTING CONCRET-E TUBES Arthur E. Troie'l,Berkeley,..Calif.

Application January 13, 1943, Serial No. 472,'283

3 Claims. ((125-128) The .present invention relates to forms for castingconcrete tubes, and particularly to forms formakingpile caps.

Pile caps, sometimes referred to as pile jackets, are usually squaretubular reenforced concrete castings which are placed over the upperends of concrete piles after they have been .driven, the caps beingcemented in place. The upper endsof the caps support the floor or wharffor which the piles serve as a foundation and may be fixed at a uniformheight, though the piles themselves are driven to different depths.

Such pile caps are preferably cast with rounded corners to preventchipping away of sharp .edges. They are usually approximately two feetin breadth and may be used in any desired lengths, but are seldom overeight feet long. Because of their size and shape, it is expedient tocast the pile caps horizontally in layers, one on top of another, sothat forms used for one layer may be raised and positioned for castingdirectly on top of the first castings as soon as the concrete has set.

It is the object of the present invention to provide forms for castingconcrete pile caps or the like which are simple in construction and easyto strip and set up. 7

A further object is the provision of a form for casting a rectangulartubular shape with an inner form member which may be easily collapsedfor withdrawal when the forms are to be stripped.

A still further object of the inventionis-a provision -in the form ofthe character described of members for producing rounded outsidecorners,

which members will not interfere with upward stripping of the verticalform walls by which they are carried, and will also leave aslightpimpression in the casting to aid in the positioning of the formsfor successive casting in vertical tiers.

Further objects and advantages of the invention are made apparent in thefollowing specification wherein detailed reference is madeto theaccompanying drawings.

In the drawings:

Fig. 1 is a central vertical section taken transversely of a formembodying the present invention and illustrating the manner in whichitis supported bypreviously made castings;

Fig.2 is a fragmentary perspective view,;i1lustrating certain details.of construction of the form illustrated in Fig. 1;

:Fig. 3 l is a horizontal sectional view taken on lineIII-JII of Fig. 1;

Fig. A -is avperspective view illustrating oneha'lf-ofone oftheform'ends shown'in Fig. 3; and

ZE'ig. .;5 is .an enlarged fragmentary perspective view showing alocking device used for securing the v.endjforms to the main inside andoutside form members.

InjFig. laconcrete pile, capA D is shown as having gbeen poured in a"form which is set up on topof ;a layer of previously. cast pile caps,portions =of whichyare indicated .at l l. The form inxzwlhi'oh thelcap.liflyhasbeen pouredincludes a pairofus'ide walls J12 (see .also Fig. 3)whichwalls are constructednf relatively thin,metal,,-plate and serve .as,forms vvfor the adjacent sides of pile capsxwfhich are castin agroup-or layer. .Being perfectly flat on :both surfaces .and preferably'beingsprayedwith alubricant before theconcrete poured, ;the walls 12,after the poured .concre'terhasv set, may be stripped by being raisedyertically. 'As the lower :ends of the .wallsextendlbelow {the bottom:ofthe casting, they may heretained, ;a s.shown,.with a few inches oftheir edge in :place between the caps :previously cast SOiaS..-;tO guide:and support them. In order that the putside. corners .of .th e..capwi1l be rounded, eachjofnthe sid walls I22 is. provided with .a .pair ofconcave fillets. at its upper. end, and a similar'ly shaped, thoughdifferently constructed, pair of.:fi11etsl:M.:at its lowerend. The upperfillets il:3.=are.'.bent to.;a shapewhich enables them to :be securelyriveted, welded, or .otherwise fastened to the Walls 12 in a,. permanentmanneras, :being positioned adjacent: the :top of the form, they .do notpreventthe :formwallfrom-being stripped upwardly from between adjacentcastings. They are preferably bent .upwardly as indicated at 15 :wherethey v:are .securedto the opposite sides of .thevimembers zl'z/and.where'they are pierced with lhQ'lBS" indicatedat :l 6, which also passthrough the members .I2.:to :proyidea purchase: by means of which the.walls may :be pulled upwardly. The lower :fillets zlikflfiSGCllTfidpermanently to the side walls, :would :prevent-their .being strippedfrom between-thecastines, :and therefore, are "formed asseparatmemberswhich, as'shown in ig. 1 *aneh l inrlac a th rupper edge byclipsx ;These clips-straddle both of the fillets I l andare shaped:to;;ret ain .-.them against the wall I2 the clips l li-beingreceivedin: notches -I8;formed at .the ;upper ends ;of slots -I*9 --which, aresomewhat ,widerthan thGEILOtChBS.

QWhen" the concretegis, poured into the form, it isqscreededsflushwyiththe top-edgesof the upper fillets ;so= thatwdueto the double thicknessof the metal of which these fillets are bent, a slight shoulder, shownat H], is left on the top surface of the casting. As the upper filletsl3 and the lower fillets I4 are of the same dimensions, this shoulder isso positioned that when the forms are stripped upwardly and the lowerfillets reset, it supports their lower edges, and when the clips ll havebeen inserted in a manner to embrace their upper edges, the form wallsmaybe pressed downwardly and will come to rest on top of the clips; thusthe weight of the walls holds the fillets E4 in place while the filletsin turn support the walls at their proper elevation. The reason for theslots l9 being somewhat wider than the notches IS in which the clips I!are received is to facilitate stripping of the side walls 12. When thesewalls are moved vertically upwardly a short distance, say a half inch orso, the clips I! are released from the notches l8 and as the wider slotsl9 pass over the clips, there is no tendency for them to bind or becomejammed in the event that the upward movement of the wall is notabsolutely vertical at all times. The inner walls of the mould are madeup of a substantially square collapsible tube which is formed of fourgenerally right angular members 20. These members are flanged inwardlyas indicated at 2| intermediate the corners of the tube and the flangesare connected together by pins 22 which also serve as pivotal supportsfor sets of links 23 (see also Fig. 3) which are pivoted at their innerends by pins 24 to the four radial webs of castings 25. Th links andcastings are spaced throughout the length of the tubular form member andthe castings are connected by rods 26, the ends of which are threadedfor reception by the threaded interiors of the castings.

The tubular form may be collapsed sufficiently to permit it to bewithdrawn from th interior of the pile cap by means of a jack screw 21at its forward end which is threaded through a nut 28 supported andbraced by links 29 connecting it with the tube by the foremost pins 22,This jack screw is connected through a swivel joint 30 with a short rod3| which is threaded into the foremost of the castings 25 and retainedtherein by a lock nut 32. Upon turning of the jack screw, which may beaccomplished by application of the wrench to its outer squared end, allof the links 23 will be moved to an inclined position and efiectivelyshortened with the result that the form walls at which their outer endsare secured will be drawn inwardly. Were the angular sections 20 of theform each made in a single piece projecting the full distance fully intoits respective corner, this inward contraction, particularly whererelatively stiff metal must be used to support the weight and pressureof the concrete, would cause the corners to be forced outwardly andwould eifect binding that would prevent extraction of the tubular formmember from the interior of the casting. Consequently, the corners havebeen constructed in the manner illustrated in Fig. 1 where they areshown as bent on a diagonal indicated at 33 with a central raised oroutwardly curved portion 34. A false corner member 35, which is formedof a separate piece of metal and in no way attached to the member 20, isused to complet the corner of the form which was lost in bending it tothe plane illustrated at 33. Sufiicient clearance is left between theoutwardly curved portion 34 and the member 35 so that when the form isdrawn inwardly or collapsed, its corners may expand slightly withoutcausing binding, and it may be Withdrawn leaving the corner form members35 in place until after the main portion of the form has been completelyremoved. These corner members 35 may then easily be loosened andextricated. In setting up the form, the lower corner members 35 arefirst put in place receiving their support from end members presently tobe described. The main rectangular member made up of the four angularmembers 20 is then inserted and thereafter the upper members 35 are slidinto place. With this construction, a collapsible inner form member ismade practical and simple to remove. The false corner members 35 may bebent to produce any degree of rounding of the inside corners of thecasting, or any other desired shape, and the slight Wedge shaped beads36, which are formed where the false corners join the members 20, may beso small as to be unnoticeable, and do not constitute a disadvantage.

The inner form member and the outer walls ID are held in properly spacedrelationship by means of end members which are illustrated at 31 in Fig.3. These end members, the construction of which is shown in Fig. 4, areformed of a rectangular plate 38 which has its central portion cut outand its inner edges flanged inward- 1y, as shown at 39, to form acomplete rectangle, while its outer edges are flanged as indicated at40, except at the corners which are rounded as shown at 4| to conform incontour to the fillets l3 and I4 which overlap them. These end wallmembers receive the inner tubular form member and are embraced on twosides by the outer members l2. They are so constructed that they may besecured either to the inner member or the outer member, and by virtue ofthis arrangement, a tube of any desired length may be cast in a form ofstandard dimensions. To determine the length of the tube, the forwardend member 31 is secured to the outer walls I2 while the rear nd member31 is secured to the inner members 20. The entire form is therefore ineffect telescopic lengthwise so that it may be set up to cast a cap ofany length.

While the end walls may be secured to the inner and outer form membersin any desired manner it is preferred that the form clamp illustrated inFig. 5 be used. In this figure one of the outer walls I2 is shown asdisposed between flanges 40 of two end members which serve as the frontwalls of adjacent forms. The forward edges of the member 12 as well asthe flanges of the end members are perforated as indicated at 42 in Fig.4 or may in some instances be provided with elongated slots as shown at43 to accommodate for slight misalignment. The clamp illustrated in Fig.5 comprises a pin 44 secured to a plate 45. The pin is passed throughaligned perforations in the members to be clamped together, and theplate 45 has a lower portion bent around the members to be clamped asindicated at 46 and a tail 4'! is bent outwardly from this lower portionfor convenience in swinging the clamp about the axis of the pin 44 sothat after the pin has been inserted, the clamp may be swung downwardlyto embrace the members 40 and the member l2 and retain them together.

Reenforcing steel may be placed in the form but is conventional in itsconstruction and arrangement, and is not here illustrated. When thecastings are poured, however, it is necessary that the concrete bevigorously agitated to prevent the occurrence of voids, particularly inthe bottom wall wherein the concrete must be poured into a horizontallydisposed area, the top of which is covered by the lower wall of theinner tubular form. To insure that this lower wall is completely poured,it is preferable that the walls of the members 20 on the lower side beprovided with small countersunk perforations as indicated at 48 in Figs.1 and 3 so that when this wall space is completely filled, smallportions of the concrete will ooze upwardly through these perforationswhere they will serve as visible indication that the space beneath themis full. These small perforations, which need not be more than a quarterof an inch in diameter, leave such a small area of roughness on theinterior of the casting that it can scarcely be detected, and due to thefact that they are countersunk, the small quantity of concrete whichflows through each perforation usually breaks away on contraction of theinner form without danger of filling the indicating perforations, thusmaking it unnecessary to clean the perforations before each castingoperation. All of the form walls, as has previously been stated, arepreferably sprayed with a lubricant before casting to facilitate theirbeing stripped and this is particularly desirable of the vertical walls12 which must be stripped upwardly from between adjacent castings. Thebottom wall, however, which is provided by the top surface of apreviously cast cap, except in the first instance where the originallayer is cast upon foundation planks suitably arranged for that purpose,may be either covered with a layer of paper to prevent adherence ofsuperimposed castings, or may be heavily lubricated for the samepurpose.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. Forms for casting rectangular tubular members including rectangularinner form members, means for contracting the walls of said members topermit them to be stripped from the castings, the corners of said innerform members being bent inwardly to clear the corners of the casting,and separable false corner forms overlying the inwardly bent portions.

2. An inner form for a rectangular tubular member comprising four platesbent to right angles and joined to form a generally rectangular tube,means for bending the walls of said tube inwardly to contract it beforestripping it from the shape cast around it, the corners of said tubebeing bent inwardly to clear the corners of the casting, and falsecorner forms slidably separable from and overlying the inwardly bentcorners.

3. An inner form for a rectangular tubular member comprising four platesbent to right angles and joined to form a generally rectangular tube,means disposed mainly within said tube and engaging said plates at theirlines of juncture to draw the walls of the tube inwardly for contractingit before it is stripped from the shape cast around it, the corners ofsaid plate being shaped to clear the corners of the casting, and cornerform members slidably separable from and overlying said shaped corners.

ARTHUR E. TROIEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

